What caused the controversy?The 200th episode of South Park — which aired last week — comes rather close to depicting Mohammad, something Muslim law forbids. The Prophet is initially heard speaking from inside a U-Haul trailer, and later emerges wearing a bear costume. In the 201st episode, a "CENSORED" box covers what is said to be the character of Mohammed, and all mentions of his name are bleeped out.

Who issued the "threat"?Twenty-year old Muslim convert Zachary Adam Chesser, a Virginia resident who now goes by the name AbuTalhah Al-Amrikee, found the jokes to be blasphemous. On the website RevolutionMuslim.com, he wrote that Parker and Stone would "probably end up" like Theo van Gogh, a Dutch filmmaker who was murdered by a Muslim extremist in 2004. His post included the home addresses of both Parker and Stone. Later, Chester told Fox News his message was "not a threat," but that the killing of the South Park creators "really is a likely outcome."

Why would he say that?In the view of many hard-line Muslims, the Koran holds that anyone who insults Mohammed must be executed. That was why Iran's Ayatollah Ruhollah Khomeini issued a fatwa, or Islamic religious ruling, calling for the death of author Salman Rushdie. The ayatollah said Rushdie had insulted Islam's founder in his novelThe Satanic Verses. The fatwa was eased in 1998, after Rushdie spent years in hiding.

So is there a fatwa against Trey Parker and Matt Stone?No, at least not officially. But a basic principle in Islamic scripture — called "commanding right and forbidding wrong" — "obligates Muslim males to police behavior seen to be wrong and personally deal out the appropriate punishment as stated in scripture," says former Dutch legislator AyaanHirsi Ali, in The Wall Street Journal. Ali says Amrikee's Web post amounts to "an unofficial fatwa."

Is there a consensus that the South Park creators are in danger?No, says Leslie Gornstein at E! Online: "The clowns behind RevolutionMuslim.com ... don't even come close to the Ayatollah's credibility." Ibrahim Hooper of the Council of American-Islam relations says the group and its website have "no credibility in the Muslim community."